The present invention relates to a grasping device for changing the bending tools on a tube bending machine of standard type.
Patent EP-0 120 336 discloses a tube bending machine which is secured on its bending jig, to a support device which merely allows the clamping jaws to be changed by a combination of vertical and horizontal movements over said bending jig.
The machine described in patent EP-0 120 336 has cycle times for performing tool changes which are too long and which slow down the production of elbows or bends in the tubes. What is more, the support device does not allow the simultaneous changing of the clamping jaws or mating jaws which correspond, respectively, to the moving jaw and to the fixed jaw of a standard tube bending machine.
To solve this problem, the applicant filed a patent application FR 98/01,315, which describes a tube bending machine comprising a barrel-type device the purpose of which was to bring the sets of clamping jaws comprising cavities of different shapes level with the bending head of the machine so that the one that corresponded to the exterior profile of the tube that was to be bent could be selected simply by rotating the barrel-type device about its longitudinal axis.
The tube bending machine (described in patent application FR 98/01,315) is secured on the bending arm to the barrel-type device carrying the sets of clamping jaws with different cavities. Each set of clamping jaws consists of a fixed jaw and a moving jaw making it possible to make an elbow, of a particular bend radius. The barrel-type device can pivot at the same time as the bending arm about the bending head so as to shape the tube.
Furthermore, the barrel-type device can move, on the one hand in rotation about its own longitudinal axis and, on the other hand, in directions contained in planes perpendicular and/or parallel to the one containing the longitudinal axis of the fixed frame.
The grasping device according to the present invention is intended to fit around a tube bending machine of standard type without modifying its structure and operation.
The grasping device is not secured to the bending head of the bending machine but is independent and placed around the latter so that during the time of the tube bending cycle it can change the tool or the sets of clamping jaws.
Grasping device for changing the bending tools on a tube bending machine of standard type, characterized in that it comprises:
a portal frame or the like placed around the bending machine over the bending head and bending arm;
a rotary head which, with respect to the portal frame has independent movements which consist of two independent or dependent rotations in different planes, a vertical movement, and a horizontal movement;
and a tool magazine which can move independently of the movements of the rotary head in a horizontal or rotary direction with respect to the portal frame.
Grasping device, characterized in that the rotary head pivots about a central axle which is inclined by an angle xcex1 with respect to a horizontal plane.
Grasping device, characterized in that the angle xcex1 is 45xc2x0 with respect to a horizontal plane.
Grasping device, characterized in that the portal frame consists of four vertical legs connected together at the upper part by four horizontal beams which are arranged in such a way that one of the beams carries the rotary head and the tool magazine.
Grasping device, characterized in that the horizontal beam is secured to guide means which collaborate with a crossmember parallel to same beam and able to move in a horizontal direction with respect to the portal frame, said crossmember comprising, on its opposite side to the one that collaborates with the guide means, a guide device which allows a support to move in a vertical direction with respect to the portal frame, said support being secured, at right angles to its vertical axle and in its lower part, to a horizontal beam which, at its free end, carries the rotary head constituting the means of grasping the tools or sets of clamping jaws.
Grasping device, characterized in that the rotary head consists of an arm which can rotate about the central axle which is secured to the horizontal beam of the support.
Grasping device, characterized in that the arm is secured at each of its ends to a pivot axle each of which collaborates with a fixing device pivoting about its respective axle to move into a vertical plane parallel to the one containing the support.
Grasping device, characterized in that each fixing device is designed to carry a set of clamping jaws which consists of a moving jaw and a fixed jaw indexed respectively on the intermediate element of the jaw support secured to the bending arm and on the bending roller of the bending head of the bending machine.
Grasping device, characterized in that the arm is secured at each of its ends to a pivot axle which is arranged in a horizontal plane parallel to the one containing the beam.
Grasping device, characterized in that the horizontal beam is secured, above the guide means, to a horizontal crossmember equipped with guide means allowing the tool magazine to slide or rotate.